The federal appeals court has declared California’s same-sex marriage ban to be unconstitutional, paving the way for a likely U.S. Supreme Court showdown on the voter-approved law. A three-judge panel of the 9th U.S. Circuit Court of Appeals in San Francisco ruled 2-1 Tuesday that Walker, a lower-court judge, interpreted the U.S. Constitution correctly in 2010 when he declared Proposition 8 to be a violation of the civil rights of gays and lesbians.

At an anti-Prop 8 rally before the hearing. (Scott Shafer/KQED)

The measure, which passed with 52 percent of the vote in 2008, outlawed same-sex unions just five months after they became legal in the state.

Lawyers for Proposition 8 sponsors and for two couples who sued to overturn the ban have said they would appeal to the Supreme Court if they did not receive a favorable ruling from the 9th Circuit.

A stay on same-sex marriage remains in effect.

A key passage from the ruling:

“Proposition 8 serves no purpose, and has no effect, other than to lessen the status and human dignity of gays and lesbians in California, and to officially reclassify their relationships and families as inferior to those of opposite-sex couples.”

Earlier today, KQED’s Scott Shafer reported from outside the court on 7th and Mission in San Francisco:

The decision was a narrow one, focusing on the proposition itself and the fact that California voters withdrew a right that had existed before Prop 8 was passed.

“Several dozen mostly supporters of same-sex marriage had gathered in front of the court awaiting the decision. A whoop went up from the crowd almost instantaneously when it was released, accompanied by honking horns from passing motorists.

The panel of judges that made the ruling is ideologically diverse, with two having been appointed by Democrats and the third by George W. Bush. That judge, N. Randy Smith, dissented, asserting that he just wasn’t convinced that Prop 8 doesn’t have a rationally related reason attached to it.

The fact that it’s not unanimous makes it a little more likely that Prop 8 backers can go to the 9th Circuit and ask for an en banc review, made up of a larger panel of 11 judges. That would delay the case from going to the U.S. Supreme Court by possibly up to a year. The losing side has 14 days to decide whether to petition the court for such a review.

One of the unknowns before the decision was whether the ruling would be a broad, having national significance, or a narrower one that focused on Prop 8 in California. The decision was a narrow one, focusing on the proposition itself and the fact that California voters withdrew a right that had existed before Prop 8 was passed. The narrower ruling might make it a little less likely that the Supreme Court would take the case up, but that remains to be seen.”

On two ancillary issues, whether Prop 8 proponents have standing to defend the law in court, and whether Judge Vaughn Walker should have recused himself because of his own long-term same-sex relationship, the court was in unanimous agreement. It ruled that proponents do have the legal right to defend a proposition in court, and that Walker’s same-sex relationship did not require his recusal.

The National Organization For Marriage, the main group supporting Proposition 8, has condemned the ruling. From the press release:

“As sweeping and wrong-headed as this decision is, it nonetheless was as predictable as the outcome of a Harlem Globetrotters exhibition game,” said Brian Brown, NOM’s president. “We have anticipated this outcome since the moment San Francisco Judge Vaughn Walker’s first hearing in the case. Now we have the field cleared to take this issue to the US Supreme Court, where we have every confidence we will prevail.”

“Today, unelected judges cast aside the will of the people of California who voted to protect traditional marriage. This decision does not end this fight, and I expect it to go to the Supreme Court. That prospect underscores the vital importance of this election and the movement to preserve our values. I believe marriage is between a man and a woman and, as president, I will protect traditional marriage and appoint judges who interpret the Constitution as it is written and not according to their own politics and prejudices.”

As for the White House response, Obama administration press secretary Jay Carney wasn’t saying much, other than this: “The president has long opposed, as you know, discriminatory efforts to deny rights and benefits to same-sex couples.”

Update 12:45 p.m. KQED reporter Caitlin Esch, at the courthouse today, recorded the following whoop that went up from the crowd of same-sex marriage supporters as soon as the ruling was released.

“I celebrate the decision by the Ninth Circuit Court today. This is a great day for marriage equality and a great day for California families. The Court affirmed today that there is nothing in the Constitution that allows discrimination and we are on our way to protecting the fundamental rights of everyone in our State.

And, we will continue the fight until everyone is treated equally.

San Francisco stands ready to begin marrying same sex couples, and we remain as deeply committed to the fight for marriage equality today as we did nearly eight years ago when then Mayor Gavin Newsom started one of the most important civil rights issues of our generation to ensure equality for all.

I would also like to acknowledge the tireless work of our City Attorney Dennis Herrera and his team in defense of marriage equality and the California Constitution these last eight years. Together, we will take this fight all the way to the nation’s highest court, if necessary.”

“Even the most conservative judge … Randy Smith, kept asking the attorney who was defending Prop 8, ‘Please give me some legitimate government interest for why you want to prohibit gay marriage,’ and didn’t seem to get any from him,” she said.